Druid provides fast analytical queries, at high concurrency, on event-driven data. Druid can instantaneously ingest streaming data and provide sub-second queries to power interactive UIs.
Druid integrates natively with message buses (Kafka, AWS Kinesis, etc) and data lakes (HDFS, AWS S3, etc). Druid works especially well as a query layer for stream hubs and stream processors.
Druid can be deployed in any *NIX environment on commodity hardware, both in the cloud and on premise. Druid is cloud-native: scaling up and down is as simple as adding and removing processes.